Pediatric neurotransmitter diseases (PNDs) are a heterogeneous group of inborn errors of metabolism affecting the central nervous system (CNS) in children and adults. Neurotransmitters such as dopamine, epinephrine, serotonin and GABA are critical in CNS activities that include regulation of body temperature and pain threshold, control of behavior and motor function, neuronal excitation and inhibition, memory, and many other body processes. The identification of new neurotransmitter defects is growing. The most accurately defined and described PNDs to date and those that will be discussed at this conference include: aromatic L- amino acid decarboxylase deficiency (AADC), guanosine triphosphate cyclohydrolase deficiency (Segawa's disease or DOPA-responsive dystonia, GTPCH), tyrosine hydroxylase deficiency (TH), succinic semialdehyde dehydrogenase deficiency (SSADH), and sepiapterin reductase deficiency (SR). Although considered rare, the incidence of these diseases is on the rise. In some part, that rise in diagnosed cases is the result of efforts directed at educating the medical community on protocols for the testing and diagnosis of PNDs. With the increased number of diagnosed cases, an urgent need has developed for early and informed clinical intervention. A conference to educate scientists, clinicians and lay persons on the medical management of PNDs is critical to addressing that need at this time. The 1.5-day conference will update researchers, clinicians, and lay persons on current research on PNDs; educate them on existing treatments and potential future treatments; and engage them in a focused discussion on multidisciplinary treatment strategies. We expect to build substantially on our introductory conference of 2002. Attendees will include scientists, clinicians, and other health care professionals in the areas of metabolism, genetics, and neurology, as well as lay community members who have an active interest in PNDs. Because of the importance of young investigators to the treatment of PNDs, their involvement will be encouraged with specific efforts made to facilitate the participation of women and minority professionals. We also will encourage the attendance of parents whose children are affected by PNDs as their perspectives are immensely valuable to understanding these diseases. The conference will serve as a vehicle for enhancing education on clinical management of PNDs and for the development of treatment advances. Our intent is to extend the reach of the conference through the publication of the proceedings in a journal as done with the First Symposium on Pediatric Neurotransmitter Diseases, which had papers published in a supplement to the high-impact Annals of Neurology. [unreadable] [unreadable] [unreadable]